MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
DECEMBER, 2008
(For general comments about the nature of these summaries, as well as
information on how to download the tabular cyclone track files, see
the Author's Note at the end of this summary.)
*************************************************************************
DECEMBER HIGHLIGHTS
--> Finally, after three months, a typhoon develops
--> Some more Indian Ocean activity, both north and south
*************************************************************************
WIKIPEDIA TROPICAL CYCLONE REPORTS
Short reports with satellite pictures and small-scale maps for all
tropical cyclones may be found at the following links:
http://en.wikipedia.org/wiki/2008_Atlantic_hurricane_season>
http://en.wikipedia.org/wiki/2008_Pacific_hurricane_season>
http://en.wikipedia.org/wiki/2008_Pacific_typhoon_season>
http://en.wikipedia.org/wiki/2008_North_Indian_cyclone_season>
http://en.wikipedia.org/wiki/2008-09_Southern_Hemisphere_tropical_cyclone_season>
For some storms more detailed reports have been prepared. In those cases
I will include the specific links in the reports for the applicable
tropical cyclones.
*************************************************************************
!!!!!!!!!! EXTRA FEATURE !!!!!!!!!!
A REVIEW OF THE 2008 TROPICAL CYCLONE SEASON
FOR THE NORTHERN HEMISPHERE
Following is a tabular summary of all the tropical depressions,
tropical storms, hurricanes, and typhoons which occurred in the
Northern Hemisphere between 1 January and 31 December 2008, as
reported in the Monthly Global Tropical Cyclone Summaries prepared
by the author.
(1) Number - this is the sequential cyclone number assigned by either
TPC/NHC, CPHC in Honolulu, or JTWC. If neither of these
agencies issued any warnings, no number will be given.
(2) Name - the name (if any) assigned by either TPC/NHC, CPHC, IMD,
or JMA (and PAGASA for Western North Pacific systems in
their area of warning responsibility).
(3) Dates - range of dates for which tracking information for the
cyclone is available in the Global Tropical Cyclone
Tracks files prepared by the author.
(4) Pressure - Lowest central pressure (either estimated or recorded)
during the lifetime of the cyclone. For Atlantic and
Northeastern Pacific systems these will be the values
reported in operational advisories from TPC/NHC or
CPHC. For Northwest Pacific systems the central
pressure estimates are taken from advisories issued by
the Japanese Meteorological Agency. An asterisk (*)
following the pressure indicates the reading was an
actual measured pressure normally obtained by a drop-
sonde released during an aerial reconnaissance
flight. Central pressure is given in millibars,
which is numerically equivalent to hectopascals.
(5) MSW - maximum 1-minute average sustained windspeed in knots.
For the Northwestern Pacific and North Indian Ocean
basins, these will be the highest value assigned
operationally by JTWC. For the Atlantic and Northeastern
Pacific basins, the MSW values are taken from the
official tropical cyclone reports prepared by the
TPC/NHC Hurricane Specialists and which are available
on TPC/NHC's website: http://www.nhc.noaa.gov> .
(6) Basins - tropical cyclone basins where the cyclone tracked during
its life:
ATL - North Atlantic, Gulf of Mexico, Caribbean Sea
NEP - North Pacific east of Longitude 180
NWP - North Pacific west of Longitude 180
(including South China Sea)
NIO - Bay of Bengal and Arabian Sea
For tropical systems in the NWP basin, two additional columns of
information are given:
(1) The tropical storm serial number assigned by the Japanese
Meteorological Agency to tropical depressions which are deemed
to have reached tropical storm intensity. This does not always
agree with JTWC's assessment.
(2) An estimate of the maximum 10-minute average sustained wind.
The value given represents the highest 10-min avg MSW assigned
by any agency. If from any warning center other than JMA, a
numbered note below identifies which center's value is given.
A number in parentheses (e.g. (1) ) following an entry refers to
a note following the entries for the given basin. A separate table
is given for each of the four Northern Hemisphere basins.
=========================================================================
ATLANTIC BASIN
NUM NAME DATES CENT PRS MSW BASIN
(mb) (kts)
-------------------------------------------------------------------------
01 Arthur 31 May-02 Jun 1004 * 40 ATL
02 Bertha 03-20 Jul 952 110 ATL
03 Cristobal 19-24 Jul 998 * 55 ATL
04 Dolly 20-28 Jul 963 * 85 ATL
05 Edouard 03-07 Aug 996 * 55 ATL
06 Fay 15-28 Aug 986 * 60 ATL
07 Gustav 25 Aug-04 Sep 941 * 130 ATL
08 Hanna 28 Aug-12 Sep 977 * 75 ATL
09 Ike 01-15 Sep 935 125 ATL
10 Josephine 02-06 Sep 994 55 ATL
-- ----- 23-26 Sep 990 55 ATL (1)
11 Kyle 25-29 Sep 984 75 ATL
12 Laura 26 Sep-05 Oct 994 50 ATL (2)
13 Marco 06-08 Oct 998 * 55 ATL
14 Nana 12-14 Oct 1004 35 ATL
15 Omar 13-21 Oct 958 * 115 ATL
16 ----- 14-16 Oct 1004 25 ATL
17 Paloma 05-10 Nov 944 * 125 ATL
NOTES:
(1) System was a frontal hybrid which developed pronounced subtropical
cyclone characteristics before moving onshore in the Carolinas.
Convection was quite well-organized but surface data showed the LOW
to still have a frontal structure. In its earlier stages, as an
extratropical storm, the system had produced hurricane-force winds.
(2) This system was named as a subtropical storm and later acquired
tropical cyclone characteristics.
=========================================================================
NORTHEAST PACFICIC BASIN
NUM NAME DATES CENT PRS MSW BASIN
(mb) (kts)
-------------------------------------------------------------------------
01E Alma 29-31 May 994 55 NEP
02E Boris 27 Jun-04 Jul 985 70 NEP
03E Cristina 27 Jun-01 Jul 1000 45 NEP
04E Douglas 02-04 Jul 1003 35 NEP
05E ----- 05-07 Jul 1005 30 NEP
06E Elida 12-19 Jul 970 90 NEP
07E Fausto 16-22 Jul 977 80 NEP
08E Genevieve 21-27 Jul 987 65 NEP
09E Hernan 06-13 Aug 956 105 NEP
01C Kika 07-12 Aug 1007 35 NEP
10E Iselle 13-17 Aug 999 45 NEP
11E Julio 23-26 Aug 998 45 NEP
12E Karina 02-03 Sep 1000 35 NEP
13E Lowell 07-12 Sep 998 45 NEP
14E Marie 01-06 Oct 984 70 NEP
15E Norbert 04-12 Oct 945 115 NEP
16E Odile 08-12 Oct 997 50 NEP
17E ----- 23-24 Oct 1008 30 NEP
18E Polo 02-05 Nov 1003 40 NEP
=========================================================================
NORTHWEST PACFICIC BASIN
JTWC NAME(S) JMA DATES CENT MSW MSW BASIN
NUM TROP STM PRS 1-MIN 10-MIN
NUM (mb) (kts) (kts)
-------------------------------------------------------------------------
01W ----- ---- 13-18 Jan 1004 35 30 NWP
02W Neoguri/Ambo 0801 13-19 Apr 960 95 80 NWP
03W Rammasun/ (1) 0802 06-13 May 915 135 105 NWP
04W Matmo/Dindo 0803 14-17 May 994 40 45 NWP
05W Halong/Cosme 0804 13-23 May 975 70 60 NWP
06W Nakri/Enteng 0805 26 May-09 Jun 930 125 105 NWP
07W Fengshen/Frank 0806 17-27 Jun 945 95 90 NWP
--- Gener ---- 04-07 Jul 1000 -- 30 NWP (2)
08W Kalmaegi/Helen 0807 12-21 Jul 960 90 75 NWP
--- ----- ---- 13-15 Jul 1004 -- 30 NWP (3)
09W Fung-wong/Igme 0808 23-30 Jul 960 95 85 NWP
10W Kammuri/Julian 0809 03-08 Aug 975 50 50 NWP
--- Phanfone 0810 09-11 Aug 995 -- 40 NWP (4)
11W ----- ---- 12-15 Aug 1000 30 25 NWP
12W Vongfong 0811 14-18 Aug 992 50 40 NWP
13W Nuri/Karen 0812 17-23 Aug 955 95 75 NWP
14W Lawin ---- 25-28 Aug 1000 30 30 NWP (2)
15W Sinlaku/Marce 0813 08-22 Sep 935 125 90 NWP
16W ----- ---- 09-12 Sep 1002 35 30 NWP
17W ----- ---- 13-17 Sep 1010 30 25 NWP
18W Hagupit/Nina 0814 17-25 Sep 935 120 90 NWP
19W Jangmi/Ofel 0815 23 Sep-02 Oct 901 * 145 115 NWP
20W Mekkhala 0816 27-30 Sep 980 55 50 NWP
21W Higos/Pablo 0817 29 Sep-06 Oct 998 45 40 NWP
22W ----- ---- 13-15 Oct 1006 35 30 NWP
23W Bavi 0818 18-25 Oct 992 45 45 NWP
24W Maysak/ (5) 0819 06-14 Nov 985 60 50 NWP
25W Haishen 0820 15-21 Nov 1006 40 35 NWP
26W Noul/Tonyo 0821 15-18 Nov 996 40 40 NWP
27W Dolphin/Ulysses 0822 02-19 Dec 970 90 65 NWP
NOTES:
(1) The name assigned to Rammasun by PAGASA was Butchoy.
(2) This system was named by PAGASA.
(3) Classified as a tropical depression by JMA only.
(4) This system was treated as a tropical cyclone by JMA only.
(5) Two PAGASA names were applied to various stages in the life of this
system: Quinta and Siony.
=========================================================================
NORTH INDIAN OCEAN BASIN
NUM NAME DATES CENT PRS MSW BASIN
(mb) (kts)
-------------------------------------------------------------------------
01B Nargis 27 Apr-03 May --- 115 NIO
--- ----- 05-07 Jun --- 30 NIO
02B ----- 15-19 Sep 993 40 NIO
03B ----- 19-23 Oct 1000 35 NIO
04B Rashmi 25-27 Oct 1000 45 NIO (1)
05B Khai Muk 13-16 Nov 998 45 NIO
06B Nisha 25-28 Nov 1000 50 NIO (1)
07B ----- 04-07 Dec --- 35 NIO
NOTES:
(1) The 1000-mb CP value given above was not for the time of maximum
intensity.
**************************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico
Activity for December: No tropical cyclones
*************************************************************************
NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180
Activity for December: No tropical cyclones
*************************************************************************
NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180
Activity for December: 1 tropical depression **
1 typhoon
** - treated as a tropical depression by JMA only
Sources of Information
----------------------
Most of the information presented below is based upon tropical
cyclone warnings and significant tropical weather outlooks issued
by the Joint Typhoon Warning Center of the U. S. Air Force and
Navy (JTWC), located at Pearl Harbor, Hawaii. In the companion
tropical cyclone tracks file, I normally annotate track coordinates
from some of the various Asian warning centers when their center
positions differ from JTWC's by usually 40-50 nm or more. All
references to sustained winds imply a 1-minute averaging period
unless otherwise noted.
Michael V. Padua of Naga City in the Philippines, owner of the
Typhoon 2000 website, normally sends me cyclone tracks based upon
warnings issued by the Japanese Meteorological Agency (JMA) and the
Philippines' Atmospheric, Geophysical & Astronomical Services
Administration (PAGASA). A very special thanks to Michael for the
assistance he so reliably provides.
In the title line for each storm I have referenced all the cyclone
names/numbers I have available: JTWC's depression number, the
JMA-assigned name (if any), JMA's tropical storm numeric designator,
and PAGASA's name for systems forming in or passing through their
area of warning responsibility.
Northwest Pacific Tropical Activity for December
------------------------------------------------
After nearly three months without a typhoon, the Northwest Pacific
ended the year on a more normal note with Typhoon Dolphin tracking
northward east of the Philippines. What was unusual about Dolphin was
its origin and track. The system began life as an extratropical gale
near Iwo Jima, described a huge oval-shaped loop taking in a large chunk
of the WESTPAC, evolving into a subtropical and then tropical cyclone,
and finally ending up once more as an extratropical LOW near Iwo Jima.
A report on Dolphin follows.
JMA classified a low-pressure system in the southern South China Sea
west of northern Borneo as a minor tropical depression on 2 December,
but late in the day downgraded it to a low-pressure area. No track was
given for this system in the companion cyclone tracks file.
TYPHOON DOLPHIN
(TC-27W / TY 0822 / ULYSSES)
2 - 19 December
------------------------------------------------
Dolphin: contributed by Hong Kong, was selected to represent the Chinese
while dolphins which live in Hong Kong waters; also, the dolphin
is a mascot for Hong Kong
Typhoon Dolphin provided a very unusual and interesting, even if not
spectacular, ending to the rather quieter-than-normal 2008 typhoon
season. As a typhoon it was not particularly notable, but its origin
and pre-tropical cyclone phase were quite out of the ordinary. As early
as 2 December a High Seas Warning issued by JMA noted that a new extra-
tropical LOW had formed near 25N/143E, or roughly 100 nm east-northeast
of Iwo To, or over 650 nm south-southeast of Tokyo. The system moved
rapidly east-northeastward and intensified, reaching an intensity of
60 kts by 03/0600 UTC. The extratropical storm had reached a position
near 31N/158E, or about 850 nm northwest of Wake Island, by 0600 UTC on
4 December. After this the storm began to slowly weaken and its track
began to bend east-southeastward, gradually curving more in a southward
direction. At 0000 UTC 7 December the system reached the easternmost
point of its trajectory about 375 nm east-northeast of Wake Island, or
near 21N/173E. JMA still forecast the winds to be 50 kts, and although
I have no information regarding its nature, it seems likely that the
system by this time had taken on some hybrid/subtropical characteristics.
The LOW quickly curved to a west-southwesterly track which carried it
deeper into the tropics. JMA classified the system as a weak tropical
depression at 0000 UTC 8 December while located about 275 nm southeast
of Wake Island. The classification was lowered to 'low pressure area'
at 09/0000 UTC, but raised back to tropical depression status 24 hours
later. A STWO issued by JTWC at 0600 UTC 9 December mentioned the
system, which was then located about 440 nm northwest of Kwajalein
Atoll. At this time things didn't look too good for development. While
AMSU data showed a pronounced warm core, convection had waned and
upper-level support was dreadful with 30-40 kts of vertical shear over
the region. A 09/1954 UTC QuikScat pass showed that the LLCC had
continued to break down into a wave, and early on the 10th QuikScat
data still showed no surface westerly winds. However, shortly after the
10/0600 UTC STWO was issued, things turned around. A circulation was
shown to be rapidly consolidating and warnings were initiated on Tropical
Depression 27W at 10/1200 UTC, placing the center about 360 nm east of
Guam with 25-kt winds.
The MSW was upped to 30 kts at 10/1800 UTC as TD-27W zipped westward
at around 17-18 kts. The depression's center passed about 53 nm south
of Guam around 0900 UTC 11 December. At the same time JMA upped the
winds to 30 kts. JTWC upgraded the system to tropical storm status
at 11/1800 UTC with the center estimated to be about 285 nm northeast
of Yap. JMA followed suit 12 hours later, naming the system Tropical
Storm Dolphin. Interestingly, at the time of JTWC's upgrade, the storm
was forecast to hang on to tropical storm intensity for 24 hours then
slowly dissipate. This, of course, did not happen, although it took
Dolphin three days to reach typhoon intensity. The newly-christened
storm slowly increased in intensity during the next 24 hours as it
continued westward, reaching 55 kts by 13/0000 UTC (45 kts per JMA).
Dolphin's intensity remained steady at 55-60 kts for the next couple
of days as it continued to move westward but at a decelerating pace.
(As the system entered PAGASA's AOR around 13/1200 UTC, it was given the
local name Ulysses.)
JTWC upgraded Dolphin to typhoon status at 15/0000 UTC with the center
located approximately 535 nm east of Manila. Typhoon Dolphin/Ulysses was
tracking west-northwestward at 6 kts as it moved toward a weakness in the
subtropical ridge induced by an approaching mid-latitude trough. By
1200 UTC the cyclone had turned to a northerly course. It was at this
time that JMA upgraded Dolphin to typhoon strength, and also the time of
JTWC's estimated peak intensity of 90 kts, based on satellite intensity
estimates of 77 and 90 kts. Dolphin was capped by a mesoscale anti-
cyclone which had enhanced outflow as well as helped to buffer the
typhoon from strong vertical shear associated with the approaching
upper-level mid-latitude trough. Dolphin's estimated MSW dropped
slightly to 85 kts and remained there for 18 hours before more rapid
weakening set in. JTWC reduced Dolphin to minimal typhoon status at
16/1800 UTC with the storm now moving north-northeastward. (JMA's
10-min avg MSW estimate for Dolphin never exceeded 65 kts, and that
agency classified Dolphin as a typhoon for only 24 hours.)
Typhoon Dolphin continued to weaken as it accelerated northeastward.
It weakened to a tropical storm at 17/0600 UTC, and both JTWC and JMA
declared the former extratropical/subtropical/tropical cyclone to be
extratropical once more at 18/1200 UTC. Dolphin's remnants at this
time were located about 40 nm east of Iwo To, and the final JMA reference
to the system at 19/0000 UTC placed the weak center at 24N/145E, or only
about 125 nm from its point of origin. During its entire life cycle,
this remarkable system in essence described a huge loop taking in much
of the tropical and subtropical Western North Pacific.
Large swells affected many islands through the Pacific. As far away
as Papua New Guinea huge waves smashed into dozens of villages and towns,
rendering more than 400 people homeless. Significant wave heights of
2-3 metres were occurring around New Britain. According to Roger Edson,
it was the intensification of the subtropical LOW as it moved from
30N/160E to around 20N/175E that 'triggered' the big winds and hence the
big waves. It was not the resultant tropical LOW (later TD-27W) which
were responsible for the waves, but the 60+ kt winds over a 300-mile
wide area north of the subtropical LOW.
Following are a couple of links to information concerning the Papua
New Guinea damage:
http://news.bbc.co.uk/2/hi/asia-pacific/7775038.stm>
http://news.theage.com.au/world/png-seeks-aussie-help-after-tidal-surge-20081211-6wko.html>
Sadly, there was significant loss of life associated with Typhoon
Dolphin. According to the Wikipedia report, the M/Bca Mae Jan was a
cargo passenger ship which sank on 14 December due to rough seas caused
by the typhoon. At the time of its sinking the ship was carrying
98 people. Of these, 47 were known dead, six persons were reported
missing, and 46 people survived.
The Wikipedia report on Typhoon Dolphin may be accessed at the
following URL:
http://en.wikipedia.org/wiki/Typhoon_Dolphin_(2008)>
(Report written by Gary Padgett)
*************************************************************************
NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea
Activity for December: 1 tropical cyclone **
** - treated as a deep depression by IMD
Sources of Information
----------------------
Most of the information presented below is based upon tropical
cyclone warnings and significant tropical weather outlooks issued
by the Joint Typhoon Warning Center of the U. S. Air Force and
Navy (JTWC), located at Pearl Harbor, Hawaii. Occasionally some
information may be gleaned from the daily tropical weather outlooks
and other bulletins issued by the Indian Meteorological Department
(IMD), which is the World Meteorological Organization's Regional
Specialised Meteorological Centre (RSMC) for the basin.
The reported maximum sustained winds (MSW) are based on a 1-minute
averaging period, which is used by all U. S. civilian and military
weather services for tropical cyclone warnings. For synoptic
observations in the North Indian Ocean region, both 10-minute and
3-minute average winds are employed, but IMD makes no attempt to
modify the Dvorak scale for estimating tropical cyclone intensity;
hence, a 1-minute average MSW is implied. In the North Indian Ocean
basin JTWC usually does not initiate warnings until a system has
become well-organized and likely to attain tropical storm status
within 48 hours.
TROPICAL CYCLONE
(TC-07B)
4 - 7 December
------------------------------------
Tropical Cyclone 07B was a rather far-traveled but weak tropical
system which moved from the central Bay of Bengal westward at a low
latitude and made landfall in Sri Lanka as a weak depression. An area
of convection developed on 1 December about 800 nm east-southeast of
Colombo, Sri Lanka. Limited deep convection was loosely rotating around
a broad and poorly-defined LLCC. Vertical shear was low and the system
had favorable diffluence aloft. The next day JTWC upgraded the potential
for development to 'fair' as deep convection was beginning to wrap into
an elongated but consolidating LLCC. The system by this time was
centered about 685 nm east of Colombo. JTWC issued a TCFA at 2230 UTC
on 3 December, followed by the first warning on TC-07B at 04/0000 UTC.
This warning placed the center about 615 nm east of Colombo, or about
500 nm east of the eastern coast of Sri Lanka. The initial warning
intensity was 30 kts, and TC-07B was tracking slightly north of due
west at 5 kts. IMD classified the system as a depression at 04/0300 UTC.
The system changed little in intensity over the next couple of days
as it tracked westward. IMD upgraded it to deep depression status at
05/0000 UTC, and JTWC upped the winds to 35 kts at 06/0000 UTC when the
center located approximately 360 nm east-northeast of Colombo. The
LLCC was well-defined but partially-exposed. JTWC maintained TC-07B
as a minimal tropical storm for 24 hours, then downgraded it to 25 kts
and issued their final warning at 07/0000 UTC. A fully-exposed LLCC
was sheared about 95 nm east of cycling, disorganized deep convection.
According to an IMD outlook, by 07/1500 UTC the depression had moved
inland into Sri Lanka and weakened into a well-marked low-pressure
area. The residual LOW continued westward into the southeastern Arabian
Sea but did not regenerate. IMD never classified this system above the
deep depression stage; hence, no name was assigned.
There are no reports of damage or casualties resulting from TC-07B.
(Report written by Gary Padgett)
*************************************************************************
SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E
Activity for December: 1 severe tropical storm
Sources of Information
----------------------
The primary sources of tracking and intensity information for
Southwest Indian Ocean tropical cyclones are the warnings issued by
the Tropical Cyclone Warning Centre on La Reunion Island, part of
Meteo France (MFR), and the Regional Specialised Meteorological Centre
for the basin. However, tropical cyclones in this region are named
by the Sub-regional Tropical Cyclone Advisory Centres in Mauritius and
Madagascar with longitude 55E being the demarcation line between their
respective areas of naming responsibility. The La Reunion centre only
advises these agencies regarding the intensity of tropical systems.
References to sustained winds imply a 10-minute averaging period unless
otherwise stated.
In the companion tropical cyclone tracks file, I occasionally
annotate positions from warnings issued by the Joint Typhoon Warning
Center (JTWC) of the U. S. Air Force and Navy, located at Pearl
Harbor, Hawaii, when they differ from MFR's coordinates by usually
40-50 nm or more. The JTWC warnings are also the source of the
1-minute average maximum sustained wind values included in the
tracks file. Additionally, information describing details of
satellite imagery and atmospheric circulation features included in
the narratives is often gleaned from the JTWC warnings.
TROPICAL STORM CINDA
(MFR-04 / TC-04S)
15 - 21 December
----------------------------------------
Cinda: contributed by Mozambique
The first reference to the disturbance which ultimately developed
into Severe Tropical Storm Cinda seems to have been in a STWO issued
by JTWC at 1200 UTC on 13 December. An area of convection was persisting
approximately 290 nm southeast of Diego Garcia. A LLCC had begun to
rapidly consolidate with deep convection beginning to wrap into the
center along the southern periphery. Vertical wind shear was low and
JTWC assessed the development potential to be 'fair'. I do not have
available the STWOs for 14 and 15 December, but apparently the rapid
consolidation seen on the 13th was arrested. At 16/1800 UTC the
potential for development was still assessed as 'fair'. The disturbance
had migrated westward and by this time was located about 310 nm west-
southwest of Diego Garcia. In the meantime, MFR had initiated bulletins
on Tropical Disturbance 04 at 1200 UTC 15 December and 10-min mean winds
were estimated at 25 kts with 30-kt winds occurring locally in the
southern semicircle.
Late on the 16th the disturbance began to intensify and MFR upgraded
the classification to tropical depression status at 17/0000 UTC. At the
same time JTWC issued their first warning on TC-04S, located about
370 nm west-southwest of Diego Garcia. Deep convection had developed
over a tightly-wrapped LLCC, and Dvorak numbers were ranging from T2.0
to T2.5. After this spurt of strengthening, however, the intensity
remained static for another 24 hours or so as the system continued to
move west-southwestward across the South Indian Ocean. Late on the 17th
TC-04S began to undergo another round of intensification. This led to
Mauritius naming the system Tropical Storm Cinda at 0000 UTC 18 December.
Six hours later Cinda reached its peak intensity of 50 kts (per MFR)
while located about 450 nm southwest of Diego Garcia. (JTWC's peak 1-min
avg MSW was 55 kts--in good agreement.) Around the time that Cinda
reached its peak intensity its track took a southward turn. The storm
also began to weaken as vertical shear increased. The winds had
decreased to 40 kts by 19/0000 UTC but remained pegged there for a day
and a half as Cinda returned to a more west-southwesterly course. MFR
downgraded the tropical storm to a depression at 20/1200 UTC and to a
tropical disturbance six hours later. JTWC issued their final warning
on Cinda at 21/0000 UTC, placing the center about 480 nm northeast of
Reunion Island, and MFR issued their final bulletin on ex-Cinda six
hours later.
No damage or casualties are known to have resulted from Tropical
Storm Cinda.
(Report written by Gary Padgett)
*************************************************************************
NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E
Activity for December: 1 severe tropical cyclone (intense)
Sources of Information
----------------------
The primary sources of tracking and intensity information for
Northwest Australia/Southeast Indian Ocean tropical cyclones are
the warnings and advices issued by the Tropical Cyclone Warning
Centres at Perth, Western Australia, Darwin, Northern Territory,
and less frequently, by the centre at Jakarta, Indonesia.
References to sustained winds imply a 10-minute averaging period
unless otherwise stated.
In the companion tropical cyclone tracks file, I occasionally
annotate positions from warnings issued by the Joint Typhoon Warning
Center (JTWC) of the U. S. Air Force and Navy, located at Pearl
Harbor, Hawaii, when they differ from the Australian centres' coor-
dinates by usually 40-50 nm or more. The JTWC warnings are also the
source of the 1-minute average maximum sustained wind values included
in the tracks file. Additionally, information describing details of
satellite imagery and atmospheric circulation features included in
the narratives is often gleaned from the JTWC warnings.
SEVERE TROPICAL CYCLONE BILLY
(TC-05S)
17 - 29 December
-------------------------------------------------
An area of convection developed and persisted on 16 December roughly
200 nm west-northwest of Darwin, Northern Territory, Australia. Weak
convective banding was beginning to develop around a LLCC in the
presence of low vertical shear and favorable divergence aloft. The
Darwin TCWC began issuing advices on the developing system at 0630 UTC
on 17 December, placing the center then about 250 nm west of Darwin.
Deep convective banding wrapping into the center had developed by the
18th and JTWC issued a TCFA for the LOW. At 18/1200 UTC BoM Darwin
named the system Tropical Cyclone Billy with 40-kt winds. Billy was
moving slowly southeastward toward the Kimberley coast from a position
about 200 nm southwest of Darwin. The cyclone continued to strengthen,
reaching an initial peak intensity of 50 kts at 19/0600 UTC. This made
Billy a Category 2 cyclone on the Australian Cyclone Severity Scale.
Later on the 19th the cyclone's motion became west-southwesterly with
the center crossing the coastline north of Wyndham around 1800 UTC.
Following landfall, Billy weakened and was downgraded to a tropical
LOW at 20/0600 UTC. Over the next couple of days ex-Billy moved toward
the west just inland from the Western Australia coastline, maintaining
its structure, as inland cyclones tend to do in Australia. The LOW
moved back out over water around 0000 UTC 22 December and was immediately
re-upgraded to cyclone status. Billy turned to the west-southwest and
continued to hug the coastline for a couple of days, which slowed the
re-intensification process. Late on the 23rd, Billy began to rapidly
intensify with the MSW (10-min avg) increasing from 45 kts to a peak
of 95 kts in 24 hours. The cyclone reached its peak intensity of 95 kts
at 1800 UTC on Christmas Eve while located approximately 170 nm north-
northwest of Port Hedland. (JTWC's concurrent 1-min avg MSW was 105 kts,
in good agreement with BoM Perth.) Around 24/0000 UTC Billy displayed
a 6-nm diameter pinhole eye.
Around the time Billy peaked in intensity, its track took on a rather
pronounced west-northwesterly component. The cyclone's intensity held
rather steady through Christmas Day, but began to decline thereafter as
vertical shear increased significantly. The storm dropped below
hurricane intensity at 26/1800 UTC, and the Perth TCWC issued their final
warning at 28/1200 UTC as Billy weakened into a tropical LOW about
380 nm north-northwest of Onslow, Western Australia. The remnants of
Billy moved generally westward for another couple of days. In the
companion cyclone tracks file prepared by the author, the track
following Perth's final bulletin is based upon SAB satellite fix
bulletins. I lowered the winds to 25 kts based upon these, but a
29/1011 UTC QuikScat pass showed some 30-kt wind vectors; also, there
was some renewed convection and SAB assigned a T2.0/2.0 Dvorak rating
at 29/0830, so I raised the MSW to 30 kts for that time only. Following
this the LOW continued to weaken and the final SAB bulletin placed the
very weak center about 400 nm south-southeast of Christmas Island at
30/0830 UTC. The remnants of former Tropical Cyclone Billy continued
moving westward across longitude 90E and several days later were in
close proximity to another disturbance which developed into Severe
Tropical Storm Dongo in early January.
According to the Wikipedia report, two remote indigenous communities,
Kalumburu and Oombulgurri, were cut off by floodwaters with roads and
the airstrips closed. No other information regarding damage and/or
casualties has been received.
(Report written by Gary Padgett)
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NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E
Activity for December: No tropical cyclones
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SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E
Activity for December: 1 tropical depression
South Pacific Tropical Activity for December
--------------------------------------------
RSMC Nadi issued bulletins on three numbered disturbances during the
month of December, classifying one of them as a tropical depression.
Tropical Disturbances 01F and 03F were very short-lived and weak: 01F
formed on 1 December near the Northern Cooks and lasted only a couple of
days as it drifted westward, and 03F formed on 10 December in the Solomon
Islands area. This system apparently had no definite LLCC and all the
convection was confined to the north of the system. The second system,
02F, formed on 3 December near the Southern Cooks and moved to the south-
west for a few days. It became organized enough that Fiji upped its
classification to depression status on the 5th, but central winds never
exceeded 25 kts. I did not prepare a track for this system as it was
quite weak, but track graphics and some information may be found for all
three of these disturbances on the Wikipedia website.
*************************************************************************
SPECIAL FEATURE - SOURCES OF TROPICAL CYCLONE INFORMATION
The purpose of this section is to list some websites where many and
varied types of tropical cyclone information are archived. Many readers
will know about these already, but for the benefit of those who don't,
I wanted to include them.
(1) Aircraft Reconnaissance Information
---------------------------------------
Various types of messages from reconnaissance aircraft may be
retrieved from the following FTP site:
ftp://ftp.nhc.noaa.gov/pub/products/nhc/recon/>
Information regarding how to interpret the coded reconnaissance
messages may be found at the following URL:
http://www.nhc.noaa.gov/reconlist.shtml>
Links are also included to websites with further information about the
U. S. Air Force 53rd Weather Reconnaissance Squadron and the NOAA Air-
craft Operations Center.
(2) Archived Advisories
-----------------------
All the advisory products (public advisories, forecast/advisories,
strike probabilities, discussions, various graphics) issued by TPC/NHC
are archived on TPC's website. For the current year (using 2004 as an
example), the archived products can be found at:
http://www.nhc.noaa.gov/archive/2004/index.shtml>
Links to tropical products archives for earlier years are available at
the following URL:
http://www.nhc.noaa.gov/pastall.shtml>
JTWC warnings for past storms are archived on the NRL Monterrey website:
http://www.nrlmry.navy.mil/tc_pages/tc_home.html>
On the NRL site, the link to past years can be found in the upper left
corner of the screen.
I am not aware at the moment of any other TCWC which archives all
its tropical cyclone warning/advisory products for public access, but
if I learn of any, I will add them to this list.
(3) Satellite Imagery
---------------------
Satellite images of tropical cyclones in various sensor bands are
available on the NRL Monterrey and University of Wisconsin websites,
courtesy of Jeff Hawkins and Chris Velden and their associates. The
links are:
http://www.nrlmry.navy.mil/tc_pages/tc_home.html>
http://cimss.ssec.wisc.edu/tropic/tropic.html>
On the NRL site, the link to past years can be found in the upper left
corner of the screen. For the CIMSS site, a link to data archives is
located in the lower left portion of the screen.
Additional tropical satellite imagery, along with looping ability for
composite microwave imagery for the Western Hemisphere north of the
equator, can be found at:
(1) For the Eastern North Pacific:
http://www.ssd.noaa.gov/PS/TROP/trop-epac.html>
(2) For the Atlantic, Gulf of Mexico and Caribbean Sea:
http://www.ssd.noaa.gov/PS/TROP/trop-atl.html>
(4) Cyclone Tracking Information
--------------------------------
There is a U. S. Navy site that tracks tropical cyclones at 6-hourly
intervals which often includes pre and post-advisory positions. The
link to the site is:
http://www.nrlmry.navy.mil/atcf_web/doc_archives/>
Steve Young has compiled many of these tracks onto a single webpage
which is very user-friendly:
http://home.earthlink.net/~shy9/tc1.htm>
I'm sure there are other sites with available imagery available, and
as I learn of them, I will add the links to this list.
*************************************************************************
EXTRA FEATURE
In order to shorten the amount of typing in preparing the narrative
material, I have been in the habit of freely using abbreviations and
acronyms. I have tried to define most of these with the first usage
in a given summary, but I may have missed one now and then. Most of
these are probably understood by a majority of readers but perhaps a
few aren't clear to some. To remedy this I developed a Glossary of
Abbreviations and Acronyms which I first included in the August, 1998
summary. I don't normally include the Glossary in most months in
order to help keep them from being too long. If anyone would like to
receive a copy of the Glossary, please e-mail me and I'll be happy
to send them a copy.
*************************************************************************
AUTHOR'S NOTE: This summary should be considered a very preliminary
overview of the tropical cyclones that occur in each month. The cyclone
tracks (provided separately) will generally be based upon operational
warnings issued by the various tropical cyclone warning centers. The
information contained therein may differ somewhat from the tracking and
intensity information obtained from a "best-track" file which is based
on a detailed post-seasonal analysis of all available data. Information
on where to find official "best-track" files from the various warning
centers will be passed along from time to time.
The track files are not being sent via e-mail. They can be retrieved
from the archive sites listed below. (Note: I do have a limited e-mail
distribution list for the track files. If anyone wishes to receive
these via e-mail, please send me a message.)
Both the summaries and the track files are standard text files
created in DOS editor. Download to disk and use a viewer such as
Notepad or DOS editor to view the files.
The first summary in this series covered the month of October,
1997. Back issues can be obtained from the following websites
(courtesy of Michael Bath, Michael V. Padua, Michael Pitt, and
Chris Landsea):
http://australiasevereweather.com/cyclones/>
http://www.typhoon2000.ph>
http://mpittweather.com>
ftp://ftp.aoml.noaa.gov/hrd/pub/landsea/padgett/>
Another website where much information about tropical cyclones may
be found is the website for the UK Meteorological Office. Their site
contains a lot of statistical information about tropical cyclones
globally on a monthly basis. The URL is:
http://www.metoffice.gov.uk/weather/tropicalcyclone>
TROPICAL CYCLONE REPORTS AVAILABLE
JTWC now has available on its website the Annual Tropical Cyclone
Report (ATCR) for 2007 (2006-2007 season for the Southern Hemisphere).
ATCRs for earlier years are available also.
The URL is: http://metocph.nmci.navy.mil/jtwc.php>
Also, TPC/NHC has available on its webpage nice "technicolor"
tracking charts for the 2007 Atlantic and Eastern North Pacific
tropical cyclones; also, storm reports for all the 2007 Atlantic
and Eastern North Pacific cyclones are now available, as well as
track charts and reports on storms from earlier years.
The URL is: http://www.nhc.noaa.gov>
A special thanks to Michael Bath of McLeans Ridges, New South Wales,
Australia, for assisting me with proofreading the summaries.
PREPARED BY
Gary Padgett
E-mail: [email protected]
Phone: 334-222-5327
Kevin Boyle (Northwest Pacific)
E-mail: [email protected]
*************************************************************************
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